Ticagrelor Versus Clopidogrel in Patients with Late or Very Late Stent Thrombosis

G protein-coupled purinergic P2Y receptor oligomerization: Pharmacological changes and dynamic regulation

P2Y receptors (P2YRs) are a δ group of rhodopsin-like G protein-coupled receptors (GPCRs) with many essential functions in physiology and pathology, such as platelet aggregation, immune responses, neuroprotective effects, inflammation, and cellular proliferation. Thus, they are among the most researched therapeutic targets used for the clinical treatment of diseases (e.g., the antithrombotic drug clopidogrel and the dry eye treatment drug diquafosol). GPCRs transmit signals as dimers to increase the diversity of signalling pathways and pharmacological activities. Many studies have frequently confirmed dimerization between P2YRs and other GPCRs due to their functions in cardiovascular and cerebrovascular processes in vivo and in vitro. Recently, some P2YR dimers that dynamically balance physiological functions in the body were shown to be involved in effective signal transduction and exert pathological responses. In this review, we summarize the types, pharmacological changes, and active regulators of P2YR-related dimerization, and delineate new functions and pharmacological activities of P2YR-related dimers, which may be a novel direction to improve the effectiveness of medications.

Prognostic Value of D-dimer in patients with acute coronary syndrome treated by percutaneous coronary intervention: a retrospective cohort study

BACKGROUND

Associations between D-dimer and outcomes of patients with acute coronary syndromes (ACS) remain controversial. This study aimed to investigate the prognostic value of D-dimer in ACS patients treated by percutaneous coronary intervention (PCI).

METHODS

In this observational study, 3972 consecutive patients with ACS treated by PCI were retrospectively recruited. The X-tile program was used to determine the optimal D-dimer thresholds for risk stratifications. Cox regression with multiple adjustments was used for outcome analysis. Restricted cubic spline (RCS) analysis was performed to assess the dose-response association between D-dimer and outcomes. The C-index was calculated to evaluate the additional prognostic value of D-dimer when added to clinical risk factors and commonly used clinical risk scores, with internal validations using bootstrapping methods. The primary outcome was all-cause death.

RESULTS

During a median follow-up of 720 days, 225 deaths occurred. Based on the thresholds generated by X-tile, ACS-PCI patients with median (420-1150 ng/mL, hazard ratio [HR]: 1.58, 95 % confidence interval [CI]: 1.14-2.20, P = 0.007) and high (≥ 1150 ng/mL, HR: 1.98, 95 % CI: 1.36-2.89, P < 0.001) levels of D-dimer showed substantially higher risk of death compared to those with low D-dimer (< 420 ng/mL). RCS analysis depicted a constant relation between D-dimer and various outcomes. The addition of D-dimer levels significantly improved risk predictions for all-cause death when combined with the fully adjusted models (C-index: 0.853 vs. 0.845, P difference = 0.021), the GRACE score (C-index: 0.826 vs. 0.814, P difference = 0.027), and the TIMI score (C-index: 0.804 vs. 0.776, P difference < 0.001). The predicted mortality at the median follow-up (two years) was 1.7 %, 5.2 %, and 10.9 % for patients with low, median, and high D-dimer, respectively, which was well matched with the observed mortality (low D-dimer group: 1.2 %, median D-dimer group: 5.2 %, and high D-dimer group: 12.6 %).

CONCLUSIONS

For ACS patients treated by PCI, D-dimer level was an independent predictor for adverse outcomes, and provided additional prognostic value when combined with clinical risk factors and risk scores. Risk stratifications based on D-dimer was plausible to differentiate ACS-PCI patients with higher risk of death.